Cylinder adapted for holding master copies in machines and devices employed for reproducing images by means of scanning techniques



SePt- 10, 1968 K. F. lzMAlLov ETAL 3,400,643

CYLINDER ADAPTED FOR HOLDING MASTER COPIES IN MACHINES AND DEVICES EMPLOYED FOR REPRODUCINCT IMAGES BY MEANS OF SCANNING TECHNIQUES Filed Aug. s, 1965 TNVENTOR BY *Imi "M ATTORNEY-x United States Patent O 3,400,648 CYLINDER ADAPTED FOR HOLDING MASTER COPIES IN MACHINES AND DEVICES EM- PLOYED FOR REPRODUCING IMAGES BY MEANS OF SCANNING TECHNIQUES Kirill Fedorovich Izmalov, B. Gruzinskaya ul., 21/2, kv. 61, and Aron Davidovich Rabinovich, ul., Shukhova, 13/ 15, kv. 47, both of Moscow, U.S.S.R., and Petr Julievich Fleishmakher, prospect Mira, 4, kv. 4, Odessa U.S.S.R.

Filed Aug. 3, 1965, Ser. No. 476,886 1 Claim. (Cl. 95-77.5)

ABSTRACT OF THE DISCLOSURE An electron engraving machine cylinder intended for securing master copies in which the diameter of the cylinder can be altered and as a result thereof a smooth variation of the dimensions of the image is obtained thereacross. This is achieved by making the working surface of the cylinder in the form of radially movable separate longitudinal plates and an elastic cover envelops the working surface of the cylinder. A flexible transparent lm presses the rnaster copies against the cover.

The present invention relates to cylinders adapted for holding master copies in machines and devices reproducing images-by means of scanning techniques, such as cylinders of engraving machines with the diameter 0f the working surface being smoothly adjustable.

Known in the art are `cylinders used for similar purposes which will be further referred to as cylinders master-holders in which a smooth variation of the dimensions of the image to be obtained in the direction of the scanning lines is provided by shifting radially the longitudinal plates with an elastic cover or coating placed thereon, and a master copy being lfixed on said cover by means of a transparent film. The working surface of such cylinders master-holders is made of a resilient material enveloping the plates capable of radial travel with respect to the cylinder body.

With an increase of the diameter of the cylinder, however, the dimensions of said elastic cover and, hence, of the working surface of the cylinder, remain unchanged and the surplus area is enveloped by a material, such as cloth which is unwound from a roll, disposed in the nonoperative portion of the cylinder.

Said non-cylindrical portion of the surface enveloped by the material such as cloth cannot be used for fixing the master copy thereon and thus happens to be inoperative.

This fact brings about a deterioration in the efficiency of machines and devices of the type described above.

It is, therefore, an object of the present invention to eliminate said distadvantage inherent to cylinders master-holders used in the art.

It is a more specific object of the invention to provide a cylinder master-holder whose design will make it possible to use the entire working surface of said cylinder.

Said objects are attained due to the fact that the outer surface of the longitudinal plates is made cylindrical of a diameter close to that of the cylinder, and the cover or coating enveloping said longitudinal plates is made of a sheet of a resilient expandable rubber-like material which 3,400,648 Patented Sept. 10, 1968 ICC allows, `with the diameter being varied, the variation of the working surface of the cylinder due to -longitudinal deformations (expansion-contraction) of the sheet.

The elastic transparent `film which presses the master copy to the expandable cover, may be fixed and wound on a roll mounted above one of the longitudinal plates.

The invention is further explained in the description given below to be had in conjunction with the accompanying drawings, wherein:

FIG. l is a front view of the cylinder master-holder of the invention;

FIG. 2 is a side view of same.

The design and the operation principle of the cylinder master-holder in accordance with the invention are as follows.

In body 2 of the cylinder mounted on shaft 1 there are two rows of guiding grooves (not shown in the drawing) in which longitudinal plates 3 can travel radially, said longitudinal plates being disposed parallel to the cylinder generatrices. Longitudinal plates 3 are caused to travel by means of double cone 4, said longitudinal plates 3 bearing thereagainst with their ehamfered members 5 and 6. Double cone 4 travels forward along shaft 1 when screw 7 is being turned. Double cone 4 is retained in position and prevented from turning by detent 8 entering the longitudinal groove on the internal side of body 2 of the cylinder. Screw 7 which causes double cone 4 to travel is fixed in a required position by means of locking nut 9.

The system constituted by longitudinal plates 3 and double cone 4 is positively embraced by closed annular cover 10 made of a sheet of resilient rubber-like material. The outer surface of said cover 10 is the working surface of the cylinder master-holder, the master copies to be reproduced (photographs, drawings and the like) being placed thereon. With an increase of the diameter of the cylinder master-holder the area of its Working surface is also increased due to the resilient longitudinal deformation (expansion) of the material the cover is made of.

The master copies are pressed to the surface of annular cover 10 by means of liexible transparent film 11. One end of said transparent film 11 is fixed to plate 12 which is connected with one of longitudinal plates 3 in such a manner that it is easily detachable therefrom when master copies are placed onto the cover. The second end 0f exible transparent film 11 is fixed and partially wound on roll 13 mounted on another of said longitudinal plates 3. With the diameter of the cylinder master-holder being varied, flexible transparent film 11 is wound onto roll 13 or unwound therefrom in accordance with the variations in the dimensions of the working surface.

The outer surface of longitudinal plates is made cylindrical of a diameter close to that of the cylinder. Thereflore, the Working surface of the cylinder master-holder is, generally, not strictly cylindrical.

However, if the number of longitudinal plates 3 is sufficient for certain ranges of values within which the diameter of the cylinder master-holder may vary, the deviations of the actual working surface from the cylindrical one can be compensated by the admissible value of defocusing of the optical system of the scanning head and thus do not affect the quality of the image obtained.

What is claimed is:

1. A cylinder adapted for holding master copies in machines and devices employed for reproducing images by means of scanning techniques, such as cylinder engraving machines, with the diameter of the working surface being smoothly adjustable or variable, said cylinder providing a smooth variation of the dimensions of the image to be obtained in the direction of the scanning lines and cornprising in combination: radially movable ylongitudinal plates having a cylindrical outer surface, the diameter thereof being close to that of the cylinder master-holder; and a cover enveloping said longitudinal plates, said cover being made of a sheet of a resilient and expandable rubber-like material, which allows, with the diameter being varied due to the longitudinal deformation, variations in l I thehareamof the working surface, of said cylinder; a roll,

-mounted above one of the longitudinal .plates,-a `flexible transparent lm being Ifixed and Wound on said roll.

References Cited UNITED STATES PATENTS 2,778,093 1/1957 Mack 29-119 3,217,386 11/1965 Clendening 29--117 1o NORTON ANSHER, Prima'r'y Examiner.

GARY M. HOFFMAN, Assistant Examiner. 

